This is the mail archive of the gcc@gcc.gnu.org mailing list for the GCC project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: gcc compile-time statistics


> Date: Sat, 18 May 2002 22:13:09 -0400 (EDT)
> From: dewar@gnat.com (Robert Dewar)

> What do you think is causing the increase in time at -O0 (this
> actually is the most significant compilation time for us, since
> our customers do almost all their development at -O0 -- because
> of the debugging issues)? 

As I said, I think it's mostly caused by extra RTL complexity, at
least between 3.0 and 3.1.

> It would be interesting to include 2.8.1 in these figures, because
> we have the impression that 2.95.3 already had incurred quite a
> slow down cost. 

Sure, although I don't think it'll be very useful; it's too hard to
see what to do to the current compiler to get the time back, since the
current code is so different.

		2.8.1	2.95.3	3.0.4	3.1
tree.c -O0 -g	0.49	0.59	0.72	0.88
tree.c -O1 -g	0.67	0.87	1.06	1.40
tree.c -O2 -g	0.93	1.37	1.71	2.23

-- 
- Geoffrey Keating <geoffk@geoffk.org> <geoffk@redhat.com>


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]